09 Jul 2026
Your Watchdog Margin Is Thinner Than You Think: A Boot-Time-vs-Timeout Math Check
A board that resets itself during boot, over and over, in a tight loop — no crash dump, no kernel panic, just silence and then the power LED blinking again — is one of the more demoralizing bugs in embedded Linux. Community threads about STM32MP1 boards hitting exactly this pattern eventually converge on the same diagnosis: the watchdog timeout was shorter than the boot actually took. Engineers had to shrink the timeout on purpose just to reproduce it reliably, because in normal conditions the margin was just wide enough to hide the bug... Read more
#embedded-linux#watchdog#boot-time#u-boot#bsp#reliability